SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad3814f459f64d7aea960fac03a9a07127aa2163f534b41a99cdb4a5cf1bee4' 
  AND token = '+fv/IF2FaAHXJdxQkoqTG5eytD4uESZ2mhH0bYaWe5A=' 
  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"
    }
  }
}