SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a0e84d65c9383de5c656486b943218bc7bf3eeca1239dc839f16835d93f01f5' 
  AND token = 'hpc0FSme9Haso/ayFruZFsakCDwQXvmqQpUNWx/LcCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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