SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d34071f8c39f64afb58d9f5eea15171631c9e67c41c915b08b7d613c81595f6' 
  AND token = 'I/P77+AFBCavsal519nYo2v4yNqtz0hNbYm4siKVz3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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