SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dde2d28756b2e993eaa6f2c884bdb8e05670c2066f884ac49f37dd5ca2216a5d' 
  AND token = 'nzi/fVD8O118ZHXlAsfEzTgHJl0gn5PKW7JGOjN6aPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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