SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0c5629c6f928a2352d60edc106840907d08f5a16f9bc1de1173e75410858f04' 
  AND token = 'nfCRlyuHfN3uroxxmRJN94xRxrc2iKiHAvYIzaU4Xmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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