SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92fc5110f8f8208db31444167b8a5ed69daa1d0297d8875fcb35fa12d186a595' 
  AND token = 'nGVgiyliLvUYVfaOyCh0gYgJGlNOGVxN0tZXiEnY8KQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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