SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bf7ec37333a8ef6d7d1f9f482a52e89175c3d1dc7e136b605ca5935b12ac55a0' 
  AND token = 'BXZjxjkilVmQpGUWcnJqSs/sXPpOJejxwk4u5eO0r4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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