SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de2ed7684adf342ba7d7c83d1ee058d204703664f79e6de3fa328dd92a2b0b11' 
  AND token = '4SFgVZNhgSkKA3aSxxU6KQiANl8nxWc+KIiYYTZW5S4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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