SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c97aaee09f2d10389a41ea6bacf977b32e7c0ceb68ca03a9b31234857923c322' 
  AND token = 'BsDT00IrU29YtChDOm+TVl/UG7lacn06AX7LkftG9Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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