SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db2416fb22c02b5df5ab94f08817979ed747bfc4815f431d0a49dda80908a22b' 
  AND token = 'iATv4z8joEKHX2s2GJ7V6Eniy+9+Y3/jFF9dAcLsXOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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