SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25088448f52745239a79c1a7ba735866a77633456f540394cc66e492a384f2c2' 
  AND token = 'DHCCxoM8OLSxGSBaRw3t6QKZHoD7GezK+OER4JMPEW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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