SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5c5c7211dfe34f1aa4caa3b4817466caf8345881f54c486b913a36d6cf9efb6' 
  AND token = 'VIc8NjNfkpvP4MI9kncHyDUG1GFnwvdsfQCGAY5o7Do=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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