SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '216b64b26a2e684342ef628e11036cc3179229fc9d300b2f6dfbd01472af16dc' 
  AND token = 'o2QGhE3FqH9exD579fz/Tvrhbou18Y2wmbTPVblQxns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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