SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b58d8c81431bf5297755cd9a49b6a530391692fd2bee302439941d5e8ec77dc' 
  AND token = 'Qcgr9dNigDq81TnYTG6mOF7GTikLNa1IKYNvk0lp1XQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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