SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bc58d30431f34a3d1672572a2b57a2a8d7dc5ce1314b14d63bb8849b942692c' 
  AND token = 'FAdvq+rFJ+TIoBVZg3eK1fkpXtctms/hXYrgvrBqoC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}