SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af5f0601066956610e8e3156c14799753501253c1ab17856d48973aa7d83e577' 
  AND token = '/L2pgnoLmJtN6dGJZZ+ZVtlcAgTdSxEHOVrmAYVp1zE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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