SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f492794404208955573b1d0efc581a0aba20248e99022bf71aca1816452026d1' 
  AND token = 'H+t9x0eTTi34sbLBFFckDIpSAtDrQicpspXLXqInEeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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