SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf9a301f1650956f4c0fa335402d46a47f1d0e25bbb4f4a49915abfd088e0373' 
  AND token = 'R0uVdq+0ZOHKj/RAG2/tJBt7MAS7pGgTAnqs3k5/5P4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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