SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6b711ff65f2f6f9acafb454c098b465fd07ea635cf88bd784a03c13429b7201c' 
  AND token = 'HAVIn6BSS2/hFNszhFVGJkD74cAk7qzz3mp/FD2RNIc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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