SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0c9c5cdd707efddd78ce0cf7273fce1634760fba040c9464e26f150e48985140' 
  AND token = '+HLF3oy5G2BkbeQDxiPfJFl37/UBI1CLmIjPgJ2m65o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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