SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '372f254f344e6f0a65f134ad5451202ed4396469fbd32a82d6eab43bd7492296' 
  AND token = 'ituJMaS8clglx2FxNshEb8EFsumi8cqZ7uPIVPpfQj0=' 
  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"
    }
  }
}