SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e7c27013e7c0c5fade754abb4680ed6f0455faf09b92b3cd25c92f3d6565630a' 
  AND token = 'n2PJcPiL78FjpdQU1RlAnf6xtpvrSb7eG6tT2JaJQ88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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