SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b07503acdd6040ef6979cecba4be1e2be5cc4f73aede9e6db589541fd99ce09e' 
  AND token = 'Sr4VaVrFaMMgGTLVAcPEe1/BK6Zw5Blm01Xv69sdpks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}