SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0745a3ac524f6494853fb93090a8456858bac5404fefa6d34d8b6c4f78dfbf88' 
  AND token = 'cKONB3GVHenucpvKYqBkJn1ShHSRb3Sg3Cw6DUpcJsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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