SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5b51d8c0550371423f89a146b5dc06d7b6d5e5f030b752ec236226aead348330' 
  AND token = 'zn2uEOPCHph3I3Vpc3so0Xl0EaNKCTnefRrU2NHUWUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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