SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0335d77f4e1a0ce6522bfa6856fad4b8272bd2d1e14dc5aa9d6c9b029cc04772' 
  AND token = 'o8eDX2pSoA9rCJJCo8QG+bWKpTP1GWRY9R7ovbEoji8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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