SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c22e11855dc90ac20d38207324ba13ffbfbf758d504073bbacfcc032761c7a81' 
  AND token = '2G5rjWSSMRBDSOn1SwRREZ6vt+vgM3GPNlLOunAvEMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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