SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1bbc2fff41b3e10d9452949c66beba6f711ce116497a459019b517edad83a2bc' 
  AND token = '3pp5qlFJ4E8oORKORsJg3uEQ84grwqUHJlkqaBLiAb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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