SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0331ab433634a51bf842916dad33fd9ef4e0f9d2a5fb590405adaa13a065c55a' 
  AND token = 'gcnjUeptDMC/8HfFUEQEAmya4tjwskZFGlQ/r+ITiyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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