SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f26890a192d2994226df5426e41844761c2c7c994cae781c3311a0f22e44a77c' 
  AND token = 'dQC4voXKkEvHXpLEC5ET+C10aZrIBVRHaLmygnOwTS0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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