SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd89284bcb7b88e90c814216d7a952261fad3ddaf80c2379a648dfd3445e249e4' 
  AND token = 'vyju89CWgDRwwJf4lTxr3KdhaWq1pvl+zZCJmGqSDiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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