SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd76da5836e8840669b54ec474c064cd8b3b9c6174af9e7fdcb9025f5d006c4d7' 
  AND token = '/sqvVkARvmBeZWgT11+t1sT3hMD4kAYKgagFOmyiIOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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