SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58f6b1a683489b80ccf62fd671aac72f18bc14ece63abecbb7eb6dfdb1c6952a' 
  AND token = '8PIpSbsF3ulqA4rlK7kZLzufPYPRSQNk/MDSJH1WQsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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