SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2036ba8283e2152657aad82db9ba3becbcbb539279db30b370e7f026abb01434' 
  AND token = 'JOkOpsMUuuLBAiHnLYvRvQabJovmz6NBLh9nFhgTTpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00111

JSON explain

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