SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b32a859de208de2b57f9c5983f363aad349204cac90ebeb32c10382e82d4172f' 
  AND token = 'UQJdcAewqkeLTxlDK2SzBk/5q2daYgSxFSNOG1scJkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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