SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c842aa00ea091c431bce73c73689a1f5526e1e13394cbadd10077a52d32d1117' 
  AND token = 'GLoRI9FrvqExfqfUshqiR6ktEH78sqTNBsKp/E2g/js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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