SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a452bfede800c27b96a6caa77ebdbc88cfa19631bc51d2d9d5a88927567c8a8' 
  AND token = 'i/qz3wRfF49jAeFCQZ5kZ2EN0YLy1D8lBMWiv2J2VTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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