SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '088c5efef3f7f48065a0b5d39d5c3bfcf5870137a60149f9f2fbc94fd0dd2c78' 
  AND token = 'wTgApBbNHIKrVRqoA5QHIOfN5ejDMz6uz1cSQdLR/SE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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