SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2429798895541e65b309ce33f2c8213eede5c801bddaa8084d6764f13a14aa7a' 
  AND token = 'ghQjkyIF7HMg4hFmtSdoDQlYuH7ZMFASTztJruggeyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}