SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b24f51072d4e673f05dce251096f46a3b24e0f9c0ef3568376adba4fdc28fcdc' 
  AND token = 'HgjzQSamkMu2nJAHE75h3puLNCY01sORTa87SGc30Dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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