SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f3b1c98b890f6d46364f6a66df4efde3ad3db4f622cd686077993348fb5d382' 
  AND token = 'cPhDe2mB0HestWzwuFX1c0u2/RMWEy1KWatmnf0ET7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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