SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0bba7ffd62898fbbb345c3341bc6f1db5d32c2af583f80c2ac8293dc475ecda' 
  AND token = 'NLELD33U2Zo6520ITmDboX7h50NnqgTf7zS1uFZcTo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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