SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f4116e48cb839f55a237357162ad33515fc714ced6059bfbc8389e305085348' 
  AND token = '+Rjw9dLgKpqVrdct5/sevZsgg6faB6MrkVpqQuK4mkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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