SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7a28f77b952f078c32bfc0db5d2d7955d6e2c7196b9a34e523e53c3127f6b7b0' 
  AND token = 'C+28LlSNIEQ8a6le4xCDz+tWFTEU7aZttXXoiuMUtGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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