SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76e19a11b6d1ec0e632498d9d9540e72709a2188d43084b8417962626e4726cf' 
  AND token = 'HFMVZlEfaDPAFe7uddU23r4qFQq2Jmj1DPTP5NOErhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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