SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20345605a11a3d5d0174c72eb3486d7008f74f16936dd3e9a7940ab117559268' 
  AND token = 'aiPMesEO/VSRRi4bMNpbAFAxGH894vDNKaUFV/Oo3m8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}