SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '66ee1037e6f586de0c429724fd619471565296badcbe131e3e3d3411e506d3f0' 
  AND token = 'AgZF6iTDAWZwOyNQyxhfNVNH4SVbZxAntPMNnfMG7+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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