SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74833628fad07cadf004af6eace17096547f5ef5fe5de2a81512df9b4473fef9' 
  AND token = 'IYXIx3pqR+f4h/LVtacEDG6LXjxkkewau78f4XhLjvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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