SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '917a7a907a8fcc875838b194bde575ec5ff51c2c7d9292d6f67935b125549691' 
  AND token = 'Lr3I16S/8yRdBEVHoj+8Eg3n2ZQa9/tj5on9FkMFGow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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