SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '199fbd4a44889eaad82b33a7cf948113546b652022ef5566b7c41550a746fef3' 
  AND token = 'hujhrGDxXFRLBD+8ggVnC4M993UUsZTiMdaruhnZFSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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